中文摘要：

本文采用KMnO4在不同酸溶液中的氧化还原反应,合成MnO2纳米结构,利用XRD和HRTEM对样品的晶体结构、形貌和微观结构进行表征分析.结果表明,KMnO4在无机酸（H2SO4,HCl和HNO3）和有机酸（C2H4O2）中发生反应均能制备MnO2纳米材料;通过调节溶液pH值和反应温度等参数可以控制MnO2形貌和晶体结构;在低温和较低酸浓度条件下,得到层状褶皱结构的δ-MnO2微球,而在高温和较高酸浓度条件下,可制备出一维α-MnO2单晶纳米棒.同时对在这些不同反应系统中制备MnO_2纳米材料的反应机理进行了研究.

英文摘要：

Nanostructure MnO_2 single crystal was prepared through redox reactions of potassium permanganate in different inorganic acid（hydrochloric acid,sulfuric acid and nitric acid）and organic acid（acetate）.The products were characterized by TEM and XRD.It indicated that the crystal structure and morphology of the synthesized MnO_2 can be tailored by adjusting the pH value in solution and reaction temperature.It was also found that layer foldedδ-MnO_2 microspheres were obtained at low reaction temperature and low hydrochloric acid concentration,whereasα-MnO_2 single-crystal nanorods were fabricated with increased reaction temperature and hydrochloric acid concentration. The possible formation mechanism ofδ-MnO_2 microspheres andα-MnO_2 nanorods is also discussed.